Comparative accuracy of cone-beam computed tomography and ıntegrated electronic apex locator in apically resected teeth: an ex vivo study.

This study aimed to assess the accuracy of cone-beam computed tomography (CBCT), electronic apex locator (EAL), and integrated EAL (IEAL) within endodontic motor mode in determining the working length (WL) for apically resected teeth. Fifty maxillary incisors underwent canal instrumentation, obturation with lateral condensation of gutta-percha, and root-end resections with bevel angles of 0° (Group 1) and 45° (Group 2). Retrograde canal preparations (3 mm (mm) depth) and retreatments using ProTaper Universal Retreatment files were performed. WL was measured using three techniques: CBCT, EAL, and IEAL. The actual working length (AWL) was determined under a stereomicroscope, defined as the point where the file tip first emerged at the apical surface. Deviations between the AWL and test methods were recorded; positive values indicated overestimation, while negative values reflected underestimation. The average and standard deviation of the absolute differences observed in the measurements revealed that Group 2 had consistently lower mean differences and narrower confidence intervals, especially for CBCT. Success rates calculated within tolerance limits of ± 0.5 mm and ± 1.0 mm indicated CBCT achieved the highest accuracy across both groups. No statistically significant differences were observed among devices. All evaluated devices offer comparable accuracy, providing reliable options for clinicians in complex endodontic treatments. Given their comparable accuracy, EALs offer a reliable and practical alternative to CBCT, especially when cost, accessibility, or radiation exposure are concerns.